According to a pixel cell of an active matrix organic EL display device, a series circuit is provided between (i) a power supply electrode 103 via which a power supply voltage Vp is supplied and (ii) a common electrode 104 via which a power supply voltage Vc is supplied (see FIG. 11). In the series circuit, a semiconductor switching element 106 is electrically connected with an organic EL thin film 108 serving as light emitting element. Moreover, a grayscale signal VD is supplied via a data signal line 101 to a gate terminal of the semiconductor switching element 106 so that the semiconductor switching element 106, which controls a light emitting current I, have predetermined electric conductivity. The grayscale signal VD is supplied to the gate terminal while a switching element 105 is turning on in response to a voltage VS supplied via a line 102. A capacitor element 107 which has a capacitance Cs in the pixel allows a gate voltage Vg to be held for a predetermined period of time so that light emission with a predetermined grayscale can be maintained.
According to a pixel configuration disclosed in Patent Literature 1, grayscale driving is carried out within a predetermined signal voltage range. According to a pixel circuit shown in FIG. 13, two current supplying lines (a line via which a current flows through a driving TFT 1101a and a line via which a current flows through a driving TFT 1101b) are selected, depending on whether a low grayscale level display or a high grayscale level display is carried out. Moreover, current supplying capacities of the respective two TFTs are set in accordance with grayscale display levels of which the respective two TFTs take their share. This allows each of the two TFTs to receive a high voltage Vgs even though a low current is supplied from each of the two TFTs. Accordingly a display can be carried out while it is being less affected by unevenness of threshold voltage.